Device for offset prevention and surface finishing in printing



Dec. 22,1925 1 566,8w

c. J. VMMARTHUR DEVICE FOR OFFSET PREVENTION AND SURFACE FINISHING IN PRINTING Filed April 21. 1924 BY W TORNE YS.

Patented Dec. 22, 1925.-

' vum'rau STATES PATENT OFFICE.

CHARLES MAOARTHUR, F GLEN RIDGE, NEW JERSEY, ASSIGNOE 'I'O CHARLES ENEU JOHNSON AND COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- 'IION OF PENNSYLVANIA.

DEVICE FOR QFFSET PREVENTION AND SURFACE FINISHING IN PRINTING.

Application filed. April 21, 1924. Serial No. 707,883. i

To all whom it may concern.-

Be it known that I, CHARLES J. MAOAR- Tm, a citizen of the United States, residing in Glen Ridge, in the county of Essex 5 and State of New Jersey, have invented a oil-fountains, shifting tympans or traveling tyne ans onrotary presses as is variously nee ed. This desideratum I attain by application to' the printed sheets or webs immediately after receiving an impression (as in superposed or multi-color printing), and at the completion of such printing, of finely divided or pulverulent material capable of be ing readily and quickly absorbed and assimilated by the substanc eacting as the vehicle for the coloring matter in the ink to set the latter against subsequent smudging. Of such materials I have found that transparent and translucent powders such as soapstones' silicate, hydrate of alumina, magnesia, starches and talc ma be used with equal results from the stan point of ready absorption and assimilation by the ink. My invention is further concerned with surface-finishing of freshly printed sheets, or webs, and I have further-found that by proper selection as between the various materials mentioned above, that both high finish and various degrees of dull finish may be secured in the surface of the printed sheets by rubbing action with the powders. In the main, my'invention is directed to the provision oi a very simple and eflicient 7 means capable of applying powdered absorbing and surface-finishing material uniformly over the entire surface or any predetermined portion of a newly printed sheet or web for assimilation by the moist ink, treating the surface of the sheet or web by rubbing action and suction to remove the surplus powder, and at the same time impart an improved finish to said surface that not only greatly enhances its appearance, but places the same in condition for immediate reception of another impression or impres- 00 sions in superimposition or upon the reverse side of the sheet or web without setting-off, smutting or transferring when brought into contact with tympans or other simllar instrmlmentalities ordinarily associated with 05 the cylinders of rotary printing presses.

Other objects and attendant advanta s will become readily apparent from the etailed description which follows of a typical embodiment of my invention, the appended claims serving to indicate precisel and definitely the features which I believe to be novel, and therefore patentable.

, In the drawings Fig. I is an illustration, partly in section and partly in elevation, showlng my improved means for treating freshly printed sheets or webs for the purpose of preventin subsequent offset and improving the finis of their surfaces.

Fig. II is a partial plan sectional view tBaken as indicated by the arrows II-II" in Fi III is a detail sectional view of the ow er dischar e nozzle taken as indicated y the arrows I II-III in Fig. II.

As shown, the device is in' a convenient form for use as an attachment for any standard type of printing press, designed either for continuous web or sheet printing, and comprises an enclosure designated comprehensively by the numeral 1, said enclosure housing a series of rolls 2-3- 4 over and about which the freshly printedsheet or web W is passed in the direction of the arrows in Fig. I. The sheet or web W enters the enclosure at one side through an opening 5, and emerges at.the-. opposite side of the casing as it pawes der an auxiliary guide roller 6. Frictionally er iS II'I communication with a verticallydj'sposedduot 14 which is attenuated toward the lower end as shown at 15, for mergence withan elongated nozzle 16 having a comparatively narrow. discharge slot 17 that I extends longtiudinally of, and in close prox imity tothe roll 2, it being co-extensive with the latter as shown in Fig. II so as. to

be capable oflcove'ring the entire width of the passin web W.

Slides 1 shiftable along the nozzle out: let 17 permit adjustment for variation in the extent of the sheet surface covered as may be desired or required. Mounted to the left hand side of the casing 1 (as considered in Fig. I) is a hopper or magazine .18 for the powdered material which is "to be used in' preventing" offset of. the newly printedink, and also for surface finishing. The

hopper 18 is triangular in cross configuration (Fig. II) and communicates with the 1 conduit 14 through an orifice 19 opposite to which is located a, pneumatic, injector 20 that receives air under pressure through a pipe 21 from any convenlent source, not

' shown. Interposed in the pipe 21 is a valve 22with arotary flapper 23 driven by a belt connection 24 from the shaft 25 of the blow-. er. By reason of this arrangement, the injector 20, isv intermittently energized with the result that the powdered material is introduced, via the orifice 19, in successive puffs into the conduit 14- to charge the air passing downward through the latter. The

pipej21 has also. interposed in it a hand valve .22? whereby the'flow of air to the injector 19-1nay be regulated or entirely shut off 'when occasion requires.

In order that the supply of powder may be replen' ished from t1me to time, the'reservoir' 18 is provided with a hinged cover 26.

Immediatel after'receiving the powder,

the printed s eet is engaged by a reciproeating brushl27 which. bears toward the top of the leading roll of the series 2 34 and serves to distribute the powder thoroughly over the sheet, and thus assures absorption and assimilation by the ink. As a means for -removing the excesspowder from thesheet during the remainder of its travel through the enclosure 1, I provide a series of rotary brushes 28 which are allocated as shown and -b ear toward. the surfaces of the rolls 2, 3, 4.

These rota brushes". 28 are preferably drive "a irection counter to that of the rotation of rolls 23-4, and serve, in addition to the function previously mentioned, to improve the surfaces of the travelling sheet by rubbing action with the powder. I

For the purpose of preventingpowder accumulation on the rotary brushes 28, I employ a pneumatically operative eliminating system which includes a series of pipes 29 extending transversely of the enclosure in the intervals between adjacent brushes. The pipes 29 have perforations set so as to direct the scavenging air against the rotating brushes, and air under pressure is conducted to them through acommon manifold 30 connected by a branch 31 preferably to the same source that supplies the injector 20.

The removal and recoveryof all the powder from the circulatory course within'the enclosure 1 may be accomplished as a result of the institution of provisions as follows: A conduit 32 at one side of the duct 14 aforementioned, also leads from the pressure outlet 13 of the blower 12, and extends laterally through the rear of the enclosure 1 for connection at the exterior with a powder collector 33 which may be in the form of a fabric bag of fine texture. Diversion of the outflow from the blower 12 throu h the conduit 32 instead of the duct 14 is" etermined by swinging of a. hinged or pivoted deflector 34 from the 'full-line position to the dotted-line position shown in Fig. I.

Thus by positioning the deflector 34 as directed, instead of circulating within the enclosure 1, the air is exhausted through the collector 33 and the powder incidentally filtered outand retained therein. When this is to be accomplished, the air to the injector 20 is of course cut off by aid of the hand valve 22 and the further supply of powder thereb interru ted. After complete recovcry of the pow er as just explained,-the de' vice may-be bodily removed from the printing press for inspection, adjustments or re placements without the possibility of any owder droppings being spilled .u on the earings or any intricate parts of t e press as might'otherwise occur through carelessness or inadvertence.

In the normal-operation of the device, it will be seen that the powder laden air escap-' ing at high velocity from the nozzle'16 1s forcibly blown upon the newly fW as the latter passes over ro plication of the powdered material is immediately followedby the rubbing action of thereciprocat'or brush 27 which not only firinted sheet effectively distrlbutes the powderbut in sures its absorption and assimilation by the ink, further pressure facilitating this end 2. The ap-' being also applied to the treated sheet or web in passing between the spring-pressed idler rollers 7 andthe driven rollers 2, 3, 4. In its continued progress through the enclosure 1 over the rolls 3-4, the web Wis subjected tothe successive rotary brushes 28 i with the result that a excess powder is removed, the treatment y said brushes with the presence of the, powder also causing impartation of either a high or a dull surface finish in accordance with the kind of powder employed as hereinbefore described; The excess powder removed from the brushes 28 and-thus restored to a state of suspension withirr the enclosure 1, is drawn into the inlet ll of the blower 12 and recirculated, the

desired extent of saturation of air with the powdered material being maintained through the pulsatingoperation of the injector 20 and control of air supply thereto by the valve 22?. The uninterrupted circulation of the air within the enclosure 1 will obviously not only prevent clogging, but effect continuous automatic normal reclaim-' ing of any excess powder so that there is no possible chance of its escape or wastage. E

The device, as will readily be seen is complete and compact so that it can be employed as a unit in connection with any standard.

form of printing press, or in multiple with similar units 1n presses designed for superposed or multi-color work, or those in which fa sheet is simultaneously printed on opposite sides. a

\ The application of them to the presses may be readily accomplished by any skilled mechanic schooled in the art to "which my invention appertains and need not therefore,

lated within the enclosure, a hopper for powdered absorbing and surface-finishing material, means whereby the powdered material is intermittently introduced into the pressure outlet of the blower, a nozzle communicating with said outlet to direct the powder laden air forcibly against the freshly printed surface, and means for finishing said comprisin surface of the web or sheet by rubbing action with the powder.

2. A devlce of the character described an enclosure through which a freshly-prmted sheet or web is passed, a blowerwhereby air is continuously circulated within the enclosure, a hopper for powdered; absorbing and surface-finishing material, a. pneumatic injector operative intermittently' to introduce powder-from sal'd hopper into the outlet of the blower, a nozzle communicating with said outlet to direct the powder-laden air forcibl against the surface of the freshly printe' web or sheet, and a reciprocating brush for finishing the surface of the web or sheet by rubbing actidn powder. v 3

displace the powdered material from the hopper aforesaid and introduce the same into the outlet of the blower, an intermittently-operat ive valve associated with the injector to induce pulsating action, and a nozzle communicating with the blower outlet to direct the powder-laden air forcibly upon the surface of the freshly printed web or sheet.

4. A device of the character described comprising an enclosure through which a fres ly-printed Web or sheet is passed, a blower whereby the air'is continuously circulated within the enclosure, means for introducing powdered absorbing and surfacefinishing material into the a r current for forcible impingement upon the printed sheet or web and assimilation by the moist ink, a series of rolls within the enclosure over and about which the web or sheet is progressed,

co-operative rotary brushes for removing the excess powdered material from the travelling sheet or web, and a pneumatic scavenging system including pipes with jet outlets for directing pressure-impelled air against the brushes to remove the powder accumulation therefrom.

5. A device of the character described com risin an enclosure through which a fres l -pr1nted web or sheet is passed, means where y air laden with powdered absorbing and surface-finishing material is continuously circulated within the enclosure, and means whereby the air flow may be diverted to the exterior for complete recovery of the powdered material from the circulatory course within the enclosure.

6. A device of the character described com rising an enclosure throughwhich a fres ly-printed web or sheet is passed, a

blower whereby air laden with. powdered absorbing and surface-finishing material is continuously circulated within the enclosure, a duct leading from the pressure outlet of the blower to direct the powder-laden'air against the surface of the freshly-printed sheet, a conduit also leading from the pressure outlet of the blower to a powder collector at the exterior, and means whereby the pressure flow of the blower may be diverted from the duct to pass into the conduit for the complete removal and collection of the powder from the circulatory course within the enclosure.

7. A device of the character described comprisin blower whereby air laden with powdered an enclosure through which a freshly-printed web or sheet is passed, a

lOQ

- pressure outlet of the blower to a continuously circulated within'the enclosure, aduct leading from the pressure outlet of f the blower to direct the'powder-laden air against the surface of the freshly printed web or sheet, a conduit also leading from (tihe w or collector, and a'swin%able deflector w ereby the outflow from the lower may be diverted measoo to pass into the conduit for complete re- 1 move] and collection of the powdered material from the circulatory course within .the

enclosure. v

In testimony whereof, I have hereunto signed m name at Kansas City, Mo., this 15 

